Watercraft propulsion means



June 21, 1966 c. H. BRAMSON 3,256,350

WATERCRAFT PROPULSION MEANS Filed July 27, 1965 IlllJ l/ 40 INVENTOR C I T Clive H. Bromson United States Patent 3,256,850 WATERCRAFT PROPULSION MEANS Clive H. Bramson, 1 Bay St, Oyster Bay, N.Y. Filed July 27, 1955, Ser. No. 475,048 11 Claims. (Cl. 11519) This invention is a continuation-in-part of my copending application Serial No. 388,828, filed August 11, 1964,

This invention relates to watercraft propulsion devices and more particularly to novel means for motivating such watercraft wherein the propulsion mechanism essentially comprises a flipper member, the density thereof or of an ancillary member incorporated therewith being smaller than the density of water to thus render said member buoyant of character.

Accordingly, the present invention is essentially directed to connecting a buoyant flipper member to a watercraft, the latter being either adapted to support a human being or simply utilizable as a toy or novelty device. The flippermember is preferably pivotally connected rearwardly of the watercraft, although it may be otherwise suitably positioned. The flipper member may be connected in a manner whereby it will be naturally buoyed upon the surface of the water or it may be attached to the watercraft whereby it will be submerged even when in the maximum buoyed state.

To efl'ectuate propulsion or movement of the watercraft, the flipper member must be acted upon by an externally applied force whereby at least a portion of said member will be depressed in the water to a level lower than its normally buoyed state. Upon removal of said force, the portion of or the entire member which was depressed will, by virtue of its natural buoyancy, or because of the buoyancy of a floatable member attached thereto, rise to its previous undepressed buoyed state or position and in so doing will act against the water to drive the watercraft in a direction opposite to said action.

The material found preferable in constructing the flipper member is expanded polystyrene having a density between 1 and 14 lb./ft. Other materials having natural floatability such as polyurethane, balsa wood or even an inflated flipper member formed of an otherwise nonbuoyant material will function in accordance with the concept disclosed herein. Or, as previously stated, an otherwise non-buoyant flipper member may be rendered buoyant by dint of a buoyant body being attached thereto. "Dhus, whether or not said flipper member is entirely formed of buoyant material, if it will rise when released, it is herein referred to as a water buoyant member.

A general object of the invention, therefore, resides in the provision of a device capable of driving a watercraft in a desired direction, the movement being derived by reason of the upward rising motion of a buoyant flipper member which is connected to the watercraft and which had previously been forced lower than its normally buoyed position.

Another object of the present invention is to provide a number of exemplary embodiments of the device including means for minimizing or at least decreasing the resistance of said flipper member when it is being forced to a lower level in the water.

Other objects and advantages of this instant watercraft propulsion device will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice of the invention, the same being realized and attained by means of the structure defined and pointed out in the appended claims.

The accompanying drawings referred to herein and constituting a part hereof, illustrate several embodiments of the invention, and together with the description, serve to explain the principles of the invention.

Patented June 21, 1966 FIGURE 1 is a perspective view of an embodiment of the flipper member provided at the rear of a watercraft;

FIGURE 2 is a side elevation of the embodiment of FIGURE 1 wherein the flipper member is floating at its normal buoyed position;

FIGURE 3 is a view of said embodiment wherein an external force applied against the flipper member has moved the latter downwardly within the water;

FIGURE 4 is a view of said embodiment wherein the force has been removed and the flipper member is moving upwardly in the water;

FIGURE 5 is an end view of the flipper member taken along line 55 of FIGURE 1, said view being in solid line, and a dotted representation showing said flipper member in a folded manner assumed when said member is forced downwardly in the water;

FIGURE 6 is a side elevational view of a modified embodiment of the invention;

FIGURE 7 is aperspective view of the flipper member used in FIGURE 6;

FIGURE 8 is a side elevational view of a still further modification of the invention; and

FIGURE 9 is a top plan view of the embodiment shown in FIGURE 7. I

It will be understood that the foregoing accompanying illustrations are merely exemplary and are for purposes of explanation but are not intended to encompass the myriad of possible shapes of the flipper member, the method of and place of attachment to a watercraft or the many feasible structural designs .which may facilitate movement of the flipper member downwardly in the water and reduce the resistance of the water thereto during such movement.

Referring now in detail to FIGURES 1-5 of the drawings, a watercraft 2 which floats upon water 4 will be observed having flipper member generally designated by numeral 6 attached at the rear thereof. Said flipper memher is, as aforedescribed, of buoyant character, and will naturally float upwardly toward the surface of a body of water whenever it is by any means forced under the water and the force is then removed. It is this upward movement of the flipper member which causes the watercraft to move in a given direction.

It will be understood that watercraft 2 may be a boat, a surfboard, or other watercraft capable of supporting a load. Said watercraft, however, may also be in the form of a water toy or novel watercraft capable of being used in any body of water including bathtub, pool, lake, ocean, etc.

The flipper member shown in FIGURES 1-5 is comprised of a pair of floatboard elements 8 and 10 which are hingedly connected by hinge 12 as shown. Thus, said elements 8 and 10 can swing toward and away from each other as shown. Hinge 12 is provided with stops 14 which limit said board elements with respect to the relative downwardly swinging motion capable thereby. Obviously, any suitable stop or limit means may be used. In the embodiment shown, hinge 12 is connected to a pivot arm 14 which is hinged by hinge 16 to the rear of watercraft 2. Of course, if elements 8 and 10 were not formed of buoyant material, a buoyant member attached to said flipper member would effectively cause said elements to rise after submersion to render such an embodiment operative as 'a water buoyant member.

Thus, when a downward force such as indicated by arrow 18 is exerted upon the flipper member, the latter will pivot downwardly into the water as shown in FIGURE 3, said board elements 8 and 10 being caused to fold toward one another as shown, thereby changing their relative normal orientation as shown in FIGURES 1, 2 and 4 to thereby reduce the surface area of the flipper member cutting through the water during the downward movement therethrough. Said hinge arrangement is referred to herein as resistance reducing means. Removal of said force will allow said member to be buoyed upwardly whereby reorientation of said member is effectuated due to the force of the water thereagainst. The reoriented opened board elements then act against the water to propel the watercraft forward in the direction of arrow 20.

The hinge stops 14 may, if desired, be arranged to limit the lower swing limit of said board elements to less than 180 whereby a V-shape will be retained during the upward movement thereof. Said flipper member may be of any suitable shape including arcuate, rectilinear, corrugated, etc. That is, e.g., the flipper member can be in the form of a U-shape or other shape which will advantageously cup the water and drive the watercraft forward as it floats upwardly. The cup-like member described in my US. Patent application Serial No. 388,828 exemplifies a form of the arcuate type flipper member.

Referring now to FIGURES 6 and 7 of the drawings, a simplified arcuate flipper member is utilized, said member being operational without employing any form of resistance reducing means of the type illustrated and hereinabove described. The arcuate flipper member 22 is connected to watercraft 24 by hinge 26. An arm 28 attached to the underside of watercraft 24 is provided with a pulley wheel 30 at one end thereof. A line 32 attached at one end to a lever 34 pivoted at 36, and to said flipper member at the other end, is adapted to pull said flipper member downwardly when said lever is moved as shown. When the lever is released, said flipper member will float upwardly as shown by the broken line designation, and thus propel said watercraft 24 in water 4 in the direction of arrow 38.

It will thus be appreciated that the flipper member may at all times be positioned beneath the surface of the water. The hinge may be in any form or means other than hinge means and may be utilized to connect said flipper member to the watercraft. 1

In the modified embodiment shown in FIGURES 8 and 9, the flipper member 40 is merely a flat board also without resistance reducing means incorporated thereon. Hinge 42 is provided to pivotally connect said member to watercraft 44. As will be noted, said flipper member may be caused to fold over upon said watercraft whereby it may be retracted when it becomes desirable to discontinue its use. The flipper member, when in use, may be forced down either by the users hands or feet, or other part of his body when the user is supported on the watercraft, or depressed by another person not upon the watercraft.

The watercraft may, as aforestated, be of any shape or suitable size and the flipper member may be attached thereto at any advantageous position. A plurality of flipper members may be utilized. For example, the watercraft may be circular or disc-shaped. Flipper members may be movably mounted in diagonally opposed relation tangentially of the disc. Each flipper member may be supported by a pivot arm about which said member can be rotated. Where two members are used and mounted as extensions of a diameter of the disc, directional control over the movement of the disc may be readily accomplished. That is, when the free ends of each flipper member face in the same direction, depression of both members will effectuate a forward motion when said members float upwardly. Where one of said members is pivoted over whereby the free ends of said members, respectively, face in opposite directions, activation of said members will cause said disc to rotate. Accordingly, a plurality of said flipper members may be utilized on the same watercraft, the form of each flipper member being variable as well.

Where a form of resistance reducing means is used, and a folding or collapsible flipper member is incorporated, said flipper member may fold, collapse or otherwise be reduced in size when it moves downwardly and cuts through the water. For example, the board elements 8 and 10 aforedescribed, may fold about a hinge which is transverse or angular with respect to the longitudinal axis of the watercraft, rather than about a hinge which is parallel or coextensive with respect to said axis as shown in the accompanying drawings.

Where a cup-like member such as disclosed in copending application Serial No. 388,828 is used, the lower wall thereof may have upwardly folding doors or other means which will open to allow water to enter the member as it is forced downward into the water and which will close as it rises upwardly in the water whereby said lower wall will return to its normal state and thus become reoriented. Thus, resistance against downward movement would effectively be reduced in consonance with the concept disclosed herein.

It will be noted that where a non-buoyant flipper member is utilized including resistance reducing means and an upward external force is provided to raise the flipper after depression thereof, forward motion will be realized. The use of a buoyant member, however, as preferably described herein, reduces the energy input required to cause propulsion and thereby provides a more highly efficient system.

What is claimed is:

1. A propulsion device for propelling a watercraft within a body of water, said device comprising a water buoyant flipper member movably connected to said watercraft whereby a force exerted upon said member is cap able of moving said member downwardly relative to the surface of the water and whereby removal of said force will allow said member to be buoyed upwardly, .whereupon the upward movement of said member will propel said watercraft.

2. A propulsion device for propelling a watercraft within a body of water, said device comprising a water buoyant flipper member connected to said watercraft whereby a force exerted upon said member is capable of moving said member downwardly relative to the surface of the water, resistance reducing means provided upon said device, said means permitting a change in the orientation of at least a portion of said member during the down- A ward movement thereof to thereby reduce the surface area of said member cutting through the water during said downward movement, and whereby removal of said force will allow said member to be buoyed upwardly, reorientation of said member being effectuated during the upward movement and whereby said upward movement of said member will propel said watercraft.

3. A device as set forth in claim 2 wherein said resistance reducing means comprises a hinge about which at least a portion of said buoyant member is pivoted.

4. A propulsion device for propelling a watercraft within a body of water, said device comprising a water buoyant flipper member pivotally connected to said watercraft whereby a force exerted upon said member is capable of moving at least a portion of said member downwardly relative to said watercraft and whereby removal of said force will allow the buoyancy of said at least a portion of said member to raise said portion relative to said watercraft, said rising movement causing said watercraft to be propelled.

5. A propulsion device for propelling a watercraft Within a body of water, said device comprising a water buoyant flipper member movably connectible to a watercraft whereby when connected, a force exerted upon said member is capable of moving said member downwardly relative to the surface of the water and whereby removal of said force will allow said member to be buoyed upwardly,

propel said watercraft.

6. A propulsion device as defined in claim 5 whereinsaid device is pivotally connectible to said watercraft.

7. A propulsion device as defined in claim 5 wherein said device is of arcuate configuration.

8. A propulsion device as defined in claim 5 wherein said water buoyant member comprises a gas inflatable flipper member.

9. A propulsion device as defined in claim 5 wherein said device includes resistance reducing means provided thereon, said means permitting a change in the orientation of at least a portion of said member during the downward movement thereof to thereby reduce the surface area of said member cutting through the water during said downward movement, and whereby reorientation of said member is effectuated during the upward movement of said member.

10. A propulsion device as defined in claim 5 comp-rising a plurality of water buoyant members.

11. A propulsion device for propelling a Watercraft within a body of water, said device comprising a flipper member movable connected to said watercraft whereby a force exerted upon said member is capable of moving said member downwardly relative to the surface of the water, resistance reducing means provided upon said device, said means permitting a change in the orientation of at least a portion of said member during the downward movement thereof to thereby reduce the surface area of said member cutting through the water during said downward movement, buoyant means capable of raising said member upwardly in the water, reorientation of said member being effectuated during the upward movement and whereby said upward movement of said memher will propel said watercraft.

References Cited by the Examiner UNITED STATES PATENTS 1,204,937 11/1916 Carley --28 2,511,323 6/1950 Briggs et al. 4695 2,726,624 1-2/19-55 Raicy 115--21 MILTON BUCHLER, Primary Examiner.

ANDREW H. FAR'RELL, Examiner. 

1. A PROPULSION DEVICE FOR PROPELLING A WATERCRAFT WITHIN A BODY OF WATER, SAID DEVICE COMPRISING A WATER BUOYANT FLIPPER MEMBER MOVABLY CONNECTED TO SAID WATERCRAFT WHEREBY A FORCE EXERTED UPON SAID MEMBER IS CAPABLE OF MOVING SAID MEMBER DOWNWARDLY RELATIVE TO THE SURFACE OF THE WATER AND WHEREBY REMOVAL OF SAID FORCE WILL ALLOW SAID MEMBER TO BE BUOYED UPWARDLY, WHEREUPON THE UPWARD MOVEMENT OF SAID MEMBER WILL PROPEL SAID WATERCRAFT. 